Yes, it’s possible to backup/restore AP One series each other using the same config.bin file.
Please be informed of the followings.

All the AP One series must be running the same firmware version. The latest firmware is 3.3.10 for all the AP One series as of 12/12/2013.

AP One 300 M has the most functions among other AP One models. Therefore, some of the functions that are dedicated to AP One 300 M won’t be reflected in other AP One models after backup/restoration and vice versa.

Yes, it’s possible to backup/restore AP One series each other using the same config.bin file.
Please be informed of the followings.

All the AP One series must be running the same firmware version. The latest firmware is 3.3.10 for all the AP One series as of 12/12/2013.

AP One 300 M has the most functions among other AP One models. Therefore, some of the functions that are dedicated to AP One 300 M won’t be reflected in other AP One models after backup/restoration and vice versa.

Well, for instance, AP One 300M is compatible with both 2412 - 2472 MHz and 5180 - 5825 MHz (these frequencies don’t operate simultaneously) while AP One is 2412 - 2472 MHz only. So if you set up 5Ghz in AP 300M, download the config.bin from it and upload it to AP One, then you only get to use 2.4Ghz in the AP One because AP One is only compatible with 2.4Ghz. This is a simple example. I hope this gives you an image of how it works.